The seas are large bodies of saltwater that cover about 71% of the Earth's surface. They are smaller than oceans and are often partially enclosed by land. The seas play a crucial role in regulating the planet's climate and supporting diverse ecosystems, including various marine life such as fish, coral reefs, and sea mammals. Seas are also important for human activities, including fishing, shipping, and recreation. Major seas include the Mediterranean Sea, the Caribbean Sea, and the Red Sea. These bodies of water provide resources and transportation routes, making them vital for economies and cultures around the world.